1. Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing the same and, more particularly, to a MESFET (Metal Semiconductor Field Effect Transistor) and a method of manufacturing the same.
2. Description of the Related Art
A GaAs MESFET as a typical MESFET has already been proposed by the present inventor in Japanese Patent Application No. 61-104693 wherein an epitaxial active layer is obtained by controlling and depositing a channel active layer region of the GaAs MESFET at an atomic layer level.
A MESFET using the above epitaxial active layer can be manufactured as a MESFET having a uniform threshold voltage. However, an application of such a MESFET to an integrated circuit in which MESFETs having different threshold voltages are formed on a single substrate is not considered at all in Japanese Patent Application No. 61-104693.